KR200209051Y1 - The infrared spectroscopy with the vacuum apparatus and the beam chopper for analysing the active of the catalysts consisting of multi-elements in heterogeneous catalytic reaction - Google Patents

Abstract

The present invention is an infrared spectroscopy apparatus for analyzing the activity of a multi-component catalyst system of heterogeneous catalytic reaction, comprising: a sample loading portion on which a sample to be measured is loaded, a vacuum chamber accommodating the sample loading portion, and sealed to prevent inflow of air; A vacuum pump connected through the pipe and the vacuum chamber to extract ambient air of the measurement sample in the vacuum chamber to make the vacuum chamber high vacuum, and any desired region on the sample loading portion on which the measurement sample is loaded; Only the infrared beam is characterized in that it comprises a beam chopper for selecting the direction of the beam to be irradiated selectively. According to the present invention having such a configuration, in the conventional conventional infrared spectroscopy apparatus, atmospheric components which are obstructive in analyzing the reaction confirmation of the gas sample in the case of heterogeneous catalytic reaction are effectively removed by the vacuum chamber and the vacuum pump, and the measuring catalyst The need to open and close the sample container when V is changed eliminates the disadvantage of not maintaining the sameness of the background signal and the analysis conditions, and the task of measuring several samples under the same analysis conditions is achieved by the rotatable beam chopper.

Description

INFRARED SPECTROSCOPY WITH THE VACUUM APPARATUS AND THE BEAM CHOPPER FOR ANALYSING THE ACTIVE OF THE CATALYSTS CONSISTING OF MULTI-ELEMENTS IN HETEROGENEOUS CATALYTIC REACTION }

The present invention relates to a sample vessel having a vacuum device and a beam chopper applied to an infrared spectroscopy apparatus, and more particularly, when analyzing a sample of a reactant and a product having a heterogeneous catalytic reaction with an infrared spectroscopy apparatus, A sample container having a vacuum device for making a vacuum and a beam chopper for selecting an infrared beam applied to a sample only to a desired area.

An infrared spectrometer is a device that analyzes the structure of a sample and reveals the properties of the sample by detecting infrared light through the sample molecules. To this end, spectroscopic instruments generally comprise a radiant energy light source, a vessel transparent to the radiation containing the sample, a device for providing a limited spectral region for measurement, a radiation detector for converting radiant energy into a useful signal (usually an electrical signal), and conversion And a signal processing device and a reading device for processing the signal. Wherein the infrared spectroscopy performs qualitative or quantitative analysis of the sample on the sample vessel using a radiation number light source in the range of about 12,800 to 10 cm ⁻¹ or infrared rays having a wavelength in the range of 0.78 to 1000 μm. These infrared spectroscopy instruments are key tools that have the advantage of being used for qualitative and quantitative analysis of almost all forms of compound molecules with covalent bonds, whether organic or inorganic.

Therefore, by applying this method to the catalytic reaction system, the gas molecules adsorbed on the surface of the catalyst and the material produced as a result of the catalytic reaction can be observed at the molecular level, and based on this, the mechanism of the catalytic reaction can be identified. Conventionally, when studying the catalytic reaction, in order to study only the catalyst itself, it was pressed in a thin disk form to measure the light transmittance as a solid sample, or in the case of powder, experiments were carried out by Diffuse Reflectance Infrared Fourier Transformation (DRIFT). In addition, the gas sample used for the catalytic reaction was filled in a sample of several tens of torr in a separate gas container, mounted on the sample device, and measured.

However, infrared spectroscopy has several limitations due to the physical properties of the infrared that mediate the measurement. First, the sample container holding the sample to be measured must be a transparent container that does not as far as possible affect the transmitted infrared light. In addition, a container that is transparent to infrared light must be able to maintain its shape to hold the sample.

For this reason, any of gases, liquids, and solids can be used for the infrared analysis sample, but only a single sample is used for the measurement. Among these, a gas sample is used by diffusing into a vacuum container. In order to detect a satisfactory spectrum, the light is reflected through a reflective surface in a short container to obtain a long optical path, which allows the light to pass through a large number of samples before exiting the container. The liquid sample is detected using a solution which is diluted in a solvent which is transparent to infrared rays to be used and contained as a sample having a known concentration. Since there is no single solvent that is transparent all over the infrared region, the solvents to be made should be selected appropriately depending on the frequency of the infrared rays used. Solid samples, on the other hand, are obtained by dispersing a solid in a liquid or solid matrix to obtain the desired infrared spectrum. In general, the solid sample should be ground so that the particle size of the sample solid is smaller than the wavelength of the infrared ray to prevent the scattering effect of the radiation.

As described above, the sample for infrared analysis may be any gas, liquid, or solid. However, since the method of loading the sample differs depending on the phase of the sample, it was measured using only a single sample. This is also due to the lack of a good transparent solvent across the infrared region, which is why sample handling is generally the most difficult and time-consuming part of infrared spectroscopy. In addition, it was cumbersome to measure only a single sample in one measurement and to reload and load another sample when measuring another sample. As a result, in heterogeneous catalysis, several samples could not be observed at the same time in one sample device, such as solid, powder or gas adsorbed in one sample device. Continuous measurements on were not possible.

Furthermore, in particular when reactants and products are to be measured by infrared spectroscopy, such as in heterogeneous catalysis, the following problems arise.

First, most of the measurement experiments performed by conventional infrared spectroscopy were generally performed at atmospheric pressure or low pressure of several tens of torr. The atmospheric components present around the sample vessel accurately analyze the change of reaction in the case of heterogeneous catalytic reaction. Create disturbing background noise,

Second, in the conventional infrared analysis method, the analysis is performed only on the sample in a single state due to the structure of the sample container. Therefore, in the case of heterogeneous catalytic reaction, each time the measuring catalyst is changed, the sample apparatus must be opened and closed and the sample is reloaded. The problem was that the background signal of the analytical process involved and the analytical conditions could not be maintained.

Due to these shortcomings, the reaction analysis of heterogeneous catalyst system has been hindered to precisely confirm the adsorption or desorption of the sample material involved in the reaction due to the noise component of the atmosphere in the sample container. In the case where an analysis experiment is to be performed, each time the measurement state is changed, the sample device must be opened and closed and the sample is remounted. Limitations were provided for comparative analysis of catalysis. The phase of a sample for infrared analysis can be either solid, liquid or gas, but this is the case when the state of the sample is a single phase. The samples on the branch were not observed at the same time in one sample device, and continuous measurements on various samples, such as injection of the reaction sample and removal of the reaction sample product, were not possible.

In order to achieve the above object, the present invention, in the infrared spectroscopy apparatus for the activity analysis of the multi-component catalyst system of the heterogeneous catalytic reaction, the sample loading portion to be loaded with the sample to be measured, and the sample loading portion is accommodated to prevent the inflow of air A vacuum chamber sealed so as to be connected through the vacuum chamber and a pipe, and a vacuum pump for extracting ambient air of the measurement sample in the vacuum chamber to make the vacuum chamber high vacuum; And a beam chopper for selecting an entrance direction of the beam so that the infrared beam is selectively irradiated only to any desired region of the image. The sample loading portion is divided into equal parts by the desired number of continuous measurements, and each of the divided equal parts is separately loaded for each desired measurement sample. In the vacuum chamber, the sample loading portion is accommodated in the central hollow portion of the flat surface of the plate. A connection flange for coupling a sample holding plate having a high thermal conductivity, a pipe that is physically coupled to one side of the sample holding plate and becomes a movement passage of air in the vacuum chamber, and a vacuum pipe connected to the pipe and a vacuum pump It further comprises a sample support consisting of. The beam chopper portion also includes a housing attached to the outside of the vacuum chamber and a beam chopper rotatable within the housing, wherein the beam chopper selectively irradiates the infrared beam only to any desired region of the sample loading portion. And a fan-shaped beam penetrating sphere having an area less than or equal to the size of one component region.

1 is an arrangement diagram of each component of a commonly used infrared spectroscopy apparatus.

Figure 2 is a perspective exploded view of the sample loading portion used in the infrared spectrometer according to the present invention.

Figure 3 is an exploded view of the sample loading unit internal component according to the present invention shown in FIG.

4 is a spectral spectrum diagram of a sample measured using a sample loading unit according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: infrared spectrometer 12: light source

16: sample container 30: detector

50: sample loading part support plate 52: sample loading part

54: sample window 62: chopper housing

66: chopper 68: beam penetration opening

Referring now to the drawings will be described the configuration and operation of the components according to the present invention in a commonly used infrared spectroscopy apparatus. FIG. 1 shows systematically the arrangement of each partial element of a commonly used infrared spectroscopy apparatus 10. The infrared beam emitted from the light source 12 is divided into two parts, some of which pass through the reference material 14, some of which pass through the sample container 16, pass through some optical instruments, and then meet again to the monochrome apparatus 20. In this monochromator, only a beam of a specific wavelength and a specific frequency can exit in the direction of the detector 30, so that information about the specific wavelength and a specific frequency is detected to know information about the sample. This information is amplified by the amplifier 32, some corrections are made via the synchronous rectifier 34, and some are processed by the filter and modulator 36 and then recorded by the synchronized motor 38 to the car art 40. .

As described in detail in the text, infrared spectroscopy is the most difficult and time consuming to prepare a sample because there is no good solution transparent to the infrared beam. The present invention solves the above-mentioned problem, which is a difficulty in infrared spectroscopic analysis, by improving the sample container 16 to provide an improved sample container for continuous measurement under vacuum conditions.

FIG. 2 shows a perspective exploded view of the sample container used in FIG. 1. FIG. In this figure, the square shape is a vacuum chamber, which accommodates the sample loading part for loading the sample inside the chamber, and the component fixed by the bolt on the right side selectively changes the direction of the infrared beam incident on the sample loading part. It is a beam chopper. The incidence direction of the infrared beam incident on the sample loading portion is indicated by reference numeral 44, which is directed toward the inside of the sample through the fan-shaped portion. Reference numeral 43 is a connecting flange portion which is connected to a vacuum pump to extract the air inside the vacuum chamber. By the action of this vacuum pump, the vacuum chamber shows a great difference in performance from the existing low pressure. Existing chambers are carried out at several tens of Torr low pressure, while the vacuum chamber according to the present invention is distinguished in terms of its effect in that it is performed at a high vacuum of 10 ^-6 or less.

This configuration prevents the influence of atmospheric molecules on the reaction by maintaining the sample loading section at high vacuum, and can effectively analyze the spectrum of the reaction molecules involved in the reaction by eliminating the presence of background signals or noise in advance.

3 is an exploded view of the internal components of the sample container of FIG. 2 in more detail. The first part is the sample part. This sample is made of a sample window 54 by mixing a catalyst powder of various components provided as a fine powder to a transparent material, for example, sodium chloride material in this example, and then providing it to the sample loading section 52. It is done. At this time, when the prepared sample window 54 is loaded on the sample loading section 52, a desired number of measurement sample components, for example, four components are provided separately. The sample window 54 is composed of a window composed of sodium chloride containing one component evenly in one region in order to separate and load the powder of the catalyst for each measurement sample according to the present invention. In order to be able to measure the catalyst of the composition at the same time consists of a quarter-shaped fan.

This configuration allows the infrared beam to selectively pass through each component constituting the catalyst system during the analysis of the catalytic reaction, so that the noise or background signal generated by opening and closing the sample device and reloading the sample each time the measurement object changes. The purpose of this study is to solve the problem of changes in the number of points and maintain the sameness of analysis conditions.

The sample window 54 thus prepared is now loaded into the sample holder 52 with a separator to protect the shape of the sample and to prevent each component from mixing with each other. This sample loading part also serves as a space holder to prevent the sample from being compressed and to maintain the magnetic position of each component without leaving the magnetic position. The sample loading part is made of silicone rubber to withstand a certain amount of pressure and is not deteriorated even when the temperature is changed by receiving heat energy transmitted from the outside. The shape of the sample portion 54 is divided according to the desired number of measurement samples. Shape, for example in this example, is manufactured to accommodate a fan shape.

The sample loading portion 52 is located in the hollow portion 53 formed in the central region of the sample loading portion support plate 50 and is protected from external pressure due to the supporting plate and the sample loading portion in accordance with the temperature of the sample loading portion support plate. Allow the temperature of my sample to be controlled. The temperature control of this configuration is very useful for the reaction of the catalyst and the analysis of the sample product according to this temperature because the effect of temperature on the reaction is very large. The temperature of the sample controlled here is performed by transferring thermal energy through the sample loading portion, which is generally in the range of -100 ° C to 200 ° C. The sample loading support plate is preferably made of copper to facilitate heat transfer to the sample loading portion and the temperature range is limited due to thermal reaction with other sample containers. For this purpose, a heat generating unit (not shown) for heating the support plate 50 is located between the sample loading unit support plates 50, and the heating unit receives power from an external power source (not shown) through the wire 51. To be supplied. In addition, a sensor unit (not shown) for measuring the temperature of the support plate is disposed between the support plates 50, that is, one side of the heat generating unit, in order to adjust to a desired temperature of the support plate 50 to be heated. The sensor unit measures the temperature of the support plate and has a temperature control function to disconnect the power when the temperature of the support plate is higher than the set temperature, and to connect the power to maintain the temperature of the support plate constant when the temperature of the support plate is lower than the set temperature. By doing so, the temperature of the sample as well as the sample loading portion located inside the hollow of the central region of the support plate can be kept constant from the support plate maintained at the set temperature.

Next, the cover 56 made of copper is positioned on the side of the sample loading part supporting plate to fix the sample window 54 located at the supporting plate hollow part 53 from the outside of the supporting plate. Up to this point, these components are for supporting the sample located in the vacuum chamber. A vacuum chamber is now formed by enclosing the hexahedral chamber to accommodate these partial elements. The vacuum chamber thus formed corresponds to a box-shaped box portion in the figure shown in FIG. 2 and the components described so far are those contained in the box. The cylindrical pipe and the connecting flange 43 protruding to the top of the box are the parts which are combined with the vacuum pipe in order to extract the air in the vacuum chamber through the inside of the pipe and send it to the vacuum pump.

3, the following reference numbers 58, 60, 62, 64, and 66 are parts of windows and beam choppers that attach outside the vacuum chamber. First reference numeral 58 is a window that serves as a passage for sealing the lid 56 and for passing an infrared beam into the vacuum chamber. The vacuum flange 60 is a component that secures this window 58 of sodium chloride to the outer wall of the vacuum chamber to prevent the ingress of air that may occur through it and to maintain the vacuum inside the chamber.

The housing 62 of the beam chopper is then fastened to the vacuum flange 60 by bolts 64 and the beam chopper 66 is positioned inside the housing 62. The beam chopper 66 is manufactured to be rotatable so as to selectively change the position at which the infrared beam is incident on the sample 54. In this example, the beam chopper is constituted by a disk-shaped beam chopper for easy rotation. In addition, in order to irradiate an infrared beam only to a predetermined region of the specimen 54, the beam chopper 66 preferably has a beam penetrating aperture 68 having a size smaller than one component region of the specimen. In this case, although the beam penetrating sphere 68 has a fan shape in FIG. 3, any of the penetrating spheres having a size equal to or smaller than the area of the measurement sample such as a circular or elliptical element is sufficient. On the other hand, the drive device may be connected to the beam chopper 68 so as to rotate the beam chopper externally.

In this example, as shown in FIG. 3, since the measurement target of the sample loaded on the sample loading section is divided into four places, once the sample is measured once, the sample container is not opened and closed for the next measurement under high vacuum conditions. Just rotate the beam chopper 90 °. Rotating 90 ° manually or pneumatically or by using a motor simply allows the infrared spectrum of the four measured samples to be continuously measured without opening and closing the sample vessel. This allows the source to eliminate the difference in background signals that can occur in separate measurements.

The above portion is the window 58 and the parts 62 and 66 of the beam chopper attached to the outside of the vacuum chamber. These parts are shown in exploded view in FIG. 2. The infrared beam incident in the arrow direction 44 shown in FIG. 2 passes through the rotating beam chopper and vacuum chamber and exits. As shown in FIG. 1, the infrared beam that carries information about the sample and exits the vacuum chamber passes through various optical instruments to the detector 30 after only components of a specific wavelength and a specific frequency are selected in the monochromator 20. Incident is measured. In addition, different wavelengths and different frequency components of the monochromator 20 are selected and repeatedly measured by the detector 30. In this way, the infrared beam carrying the information on the sample is analyzed to perform the activity analysis of the multicomponent catalyst system of the heterogeneous catalytic reaction.

The experiment using this configuration will be briefly described as an example. For example, when studying the catalytic reaction with a catalyst system supported on an alumina support using Mo as the main catalyst and Co as the cocatalyst, the reactant molecules are likely to be adsorbed to all three components. The contribution of catalytic reactions by components can not be distinguished. Thus, researchers wishing to observe the behavior of molecules on the surface need to observe all four materials under the same experimental conditions, including three materials and one catalyst system composed of these materials. In order to achieve this object, in the present apparatus, four materials to be measured are manufactured into a sample window 54 as shown in FIG. 3, and then loaded into the sample loading unit 52, and then in a vacuum chamber according to the present invention. Install it as is. When the infrared beam is irradiated to the vacuum chamber, the infrared beam is irradiated only to the area of the desired measurement sample through the quarter-piece beam penetration hole provided in the beam chopper. At this time, it is possible to observe the adsorption of reactant molecules to a specific component in the region of the sample, and then rotate the beam chopper 90 ° to measure the sample. In this way, the four measurement samples can be measured continuously in a high vacuum state without opening and closing the sample container, so that the comparative analysis can be effectively performed because the measurement is performed under the same conditions.

4 shows infrared spectra of furan adsorbed onto four types of catalyst samples. Pure alumina and molybdenum / alumina, cobalt / alumina, cobalt-molybdenum / alumina, and furan gas phase curves are shown as an example to show the difference.

The present invention solves some of the problems caused by the use of conventional infrared spectroscopy for heterogeneous catalysis. The present invention is equipped with a vacuum chamber surrounding the sample loading section and a vacuum pump which extracts air from the sample loading section to make the vacuum chamber vacuum, thereby preventing the confirmation of reaction of the gas sample involved in the heterogeneous catalytic reaction in the conventional infrared spectroscopy apparatus. Effectively removes atmospheric components. The present invention is also pre-separated, which eliminates the disadvantage of not maintaining the sameness of the background signal and the analytical conditions due to the need to open and close the sample vessel when the measuring catalyst is changed in the case of heterogeneous catalytic reactions in a conventional infrared spectroscopy apparatus. A sample loading section and a rotatable beam chopper are provided to enable continuous measurement while maintaining the same identity of the background signal and analytical conditions even when the measurement catalyst changes.

Claims (11)

In the infrared spectroscopy apparatus for the activity analysis of the multicomponent catalyst system of heterogeneous catalytic reaction, A sample loading part into which the sample to be measured is loaded; A vacuum chamber accommodating the sample loading part and sealed to prevent inflow of air; A vacuum pump connected to the vacuum chamber and a pipe to extract ambient air of the measurement sample in the vacuum chamber to make the vacuum chamber high vacuum; Infrared spectroscopy apparatus for the activity analysis of the multi-component catalyst system characterized in that it comprises a beam chopper for selecting the beam entry direction so that the infrared beam is selectively irradiated only to any desired region on the sample loading portion to which the measurement sample is loaded . The method of claim 1, wherein the sample loading portion, Infrared spectroscopy for the activity analysis of a multi-component catalyst system, characterized in that divided into equal parts by the desired number of continuous measurements, each of which is separated and loaded for each desired measurement sample. The method of claim 1, wherein in the vacuum chamber, A pipe having a high thermal conductivity sample loading part for accommodating the sample loading part in the central hollow portion of the flat surface of the plate, a pipe coupled to one side of the sample loading part support plate and serving as a movement passage of air in the vacuum chamber; And a sample support consisting of a connecting flange for coupling a vacuum pipe connected to the vacuum pump. The method of claim 3, wherein the sample loading portion support plate, Infrared spectroscopy for the activity analysis of the multi-component catalyst system, characterized in that it comprises a heat generating unit for generating heat energy on one side, and a sensor unit for detecting the temperature of the sample loading support plate to maintain a set temperature. The method of claim 4, wherein the sensor unit, Infrared spectroscopy apparatus for activity analysis of a multicomponent catalyst system, characterized in that the temperature is set between -100 ℃ to 200 ℃. The method of claim 3, wherein the sample loading portion support plate, Infrared spectroscopy apparatus for activity analysis of a multicomponent catalyst system, characterized in that made of copper. The method of claim 1, wherein the vacuum chamber, Infrared spectroscopy for the activity analysis of the multi-component catalyst system, characterized in that less than 10 ^-6 Torr by the action of the vacuum pump. The method of claim 1, wherein the beam chopper unit, And a housing attached to the outside of the vacuum chamber and a beam chopper rotatable within the housing. The method of claim 8, wherein the beam chopper, Activity analysis of a multi-component catalyst system comprising a fan-shaped beam penetrating sphere having an area less than the size of one component region in order to selectively irradiate the infrared beam only to any desired region of the sample loading portion Infrared spectroscopy device. The method according to claim 8, wherein the beam chopper, Infrared spectroscopy for the activity analysis of the multi-component catalyst system, characterized in that the drive for rotating the beam chopper is connected in order to enable continuous measurement for the various sample components under the same conditions. The method of claim 10, wherein the driving unit, A motor for generating rotational power of the beam chopper, a power supply for supplying electrical energy to the motor, a power transmission member for transmitting rotational power of the motor to the beam chopper, and externally received data of a control target to control the motor. Infrared spectroscopy apparatus for activity analysis of a multi-component catalyst system comprising a control unit.